In early education this was by far my most common source of error, so much that my parents rewarded me (with books :)) based on the number of math papers I turned in without any "careless errors" rather than based on anything involving good grades, absolute scores on math papers, effort, etc. Incorrect reasoning was fine - I was already plenty motivated to fix that. But dropping a minus sign? What did I care, I got the underlying reasoning right! ;)
What techniques do you have for reducing careless errors? How do these scale in stressful/timed situations?
I'm mostly asking this open question to those among us who are well-versed in developmental psychology (I'm mostly thinking of children) . Although, failing the actual scientific research on the topic, I guess some testable hypotheses would be great too.